The statements in this section merely provide background information related to the present disclosure and do not constitute prior art.
A quantum key distribution (QKD) system helps users safely share a key between a sender and a receiver by protecting against eavesdropping attacks by way of quantum uncertainty (randomness). The QKD system generates a raw key by using quantum communication, calculates a quantum bit error rate (QBER) of the raw key, generates a sifted key, and performs an error correction and privacy amplification on the sifted key so as to generate a final secret key.
In some approaches, a raw key generation process of the QKD system generates a raw key by filtering normally detected events after completing the transmission of quantum signals. In this case, the time taken to perform the QKD is increased by the time taken to perform the filtering. Furthermore, since the QKD system filters the detection events from a significantly large amount of data, the filtering time takes up the majority of the total time of performing QKD and thus the efficiency of QKD is potentially reduced.